What are the smallest speakers that are clean and flat down to 20hz?

I was impressed with folded horns think I will be getting familiar with some of my own. I was exposed to some low bass I could feel more than I could hear at times, like an invisible donkey kicking you in the chest. Up in the more practical musical hz they slam well and make beautiful coherent bass. If I had the space I would love some giant la scalas with matching folded horn bass' that reach for the ceiling.